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Re: simple question RF gnds
O> Wire resistance at DC is a constant and very low,
> Effecting a low Z (impedance) requires using a large surface area
> due to
> skin affect conduction occurring only around a thin surface area of
> metal
> conductors
I don't know about macro sized tubes such as used in a TC primary, but on
copper strips on a pc motherboard the skin effect only becomes
apparent(meaning lossy) around the gigahertz range.
> (one reason the Pri can be "hollow" copper tubing - solid center
> contributes little)
> becoming more important as frequency increases
> (note the "frequency" may not be obvious i.e. it relates to that
> of the
> highest freq component
> occurring say, in a discharge or a spark gap,
> each possessing much higher freq's than TC pri/sec resonant
> freq's)
>
> so wide copper straps (silver coated=very best) are preferred
> followed by
> Litz wire (lots of insulated wires bundled together effecting a
> large
> surface area)
I think litz wires were one of Nikola Tesla's inventions. Either that or
he just used them a lot. They also have decreased inductance because
each wire is like a inductor and when you put them in parallel 1/N*L. N
is the number of wires and L is the inductance of a single wire of the
strand. Unless because it is twisted this increases inductance, but I
don't know if this is significant or not. Decreased inductance decreases
AC resistance or reactance.
Bryan
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